Intel® Cyclone® 10 GX Device Design Guidelines

ID 683703
Date 11/06/2017
Document Table of Contents

I/O Termination

Voltage-referenced I/O standards require both an VREF and a termination voltage (VTT). The reference voltage of the receiving device tracks the termination voltage of the transmitting device. Each voltage-referenced I/O standard requires a unique termination setup.

Although single-ended, non-voltage-referenced I/O standards do not require termination, impedance matching is necessary to reduce reflections and improve signal integrity.

Cyclone 10 GX on-chip series and parallel termination provides the convenience of no external components. Alternatively, you can use external pull-up resistors to terminate the voltage-referenced I/O standards such as SSTL and HSTL.

Differential I/O standards typically require a termination resistor between the two signals at the receiver. The termination resistor must match the differential load impedance of the signal line. Cyclone 10 GX devices provide an optional on-chip differential resistor when using LVDS.

Table 34.  I/O Termination Checklist
Number Done? Checklist Item
1   Check I/O termination and impedance matching for chosen I/O standards, especially for voltage-referenced standards.

For more information about OCT features and limitations, refer to “I/O Features and Pin Connections”.